> your body needs a fair amount of carbs every day,
I think you're mistaken. Carb is the only macronutrient that is not required. The body can make glucose via gluconeogenesis. Take someone who has not eaten a single carb for a month and measure their blood glucose level and you will find a stable 90mg/dL. This is why Type-1 diabetics still need insulin (although much much lesser than otherwise) in spite of being on zero-carb diets.